*{
    margin:0;
    padding:0;
}
#main{
    width: 1000px;
    height: 1000px;
    background:pink;
    margin:0 auto;
}
#header{
    width: 1000px;
    height: 100px;
    background:#acece1;
   }
#content{
    width: 1000px;
    height: 900px;
    background:#d4efc3;
   }